How much velocity is needed to "hear" the ball?

[Hillhouse]

if what you're hearing is the seams rotation, why would it matter how fast it's thrown?

I am one of the worlds at seeing someone pitch and identifying how fast the ball is going. I get asked all the time "How fast do you think she's throwing?" And truth is, I have no idea. I let them use my pocket radar for that. But anyway, I can tell you that when I demo pitches for students, throw BP to hitters, I am told frequently they can hear the ball spinning when I throw it. And, I can promise you guys that when I'm throwing to a dad on a bucket for a demo or for someone to hit in BP, I would sincerely doubt I'm throwing mid 50's. I absolutely could be wrong on that cause I am horrible at measuring speed. But, I feel like I'm throwing extremely easy. Yet they hear the spin.

So, I don't have an answer to the OP's question. But, I think it's much lower than others seem to suggest.

 

[cnardone]

if what you're hearing is the seams rotation, why would it matter how fast it's thrown?

The velocity at the seams is a combination of the velocity of the ball (moving through space) AND the velocity of the seems due to the spin. Much like walking at the moving walkway at an airport. You can walk and the moving walkway combined. So less spin will need greater velocity. Hence, there is no perfect answer.

 

[daywalkerdad]

1200 rpm equates to about 13.5 mph. I would guess ball speed contributes 70-80% spin 20-30%.

 

[Hillhouse]

The velocity at the seams is a combination of the velocity of the ball (moving through space) AND the velocity of the seems due to the spin. Much like walking at the moving walkway at an airport. You can walk and the moving walkway combined. So less spin will need greater velocity. Hence, there is no perfect answer.

Fair enough. I hope by now you guys know me well enough that it doesn't surprise you when I say, I get lost on the technical stuff. All I know is what I've been told about balls that I've thrown. I truly don't believe I was throwing it 50mph or higher. But again, I'm not good at seeing speed and being able to identify how fast something is.

 

[daywalkerdad]

Fair enough. I hope by now you guys know me well enough that it doesn't surprise you when I say, I get lost on the technical stuff. All I know is what I've been told about balls that I've thrown. I truly don't believe I was throwing it 50mph or higher. But again, I'm not good at seeing speed and being able to identify how fast something is.

I could hear the ball at what I would guess was around 45 mph. I have seen many think that same velocity was 50 though.

 

[Northball]

...Much like walking at the moving walkway at an airport. You can walk and the moving walkway combined...

Throw on a pair of corduroy pants and walk on a moving walkway, you'll turn heads.